<!DOCTYPE HTML>
<html>
<head>
<title>Low Latency WebGL Canvas Test: Should render a green box with an upward pointing white arrow</title>
<style type="text/css">
.nomargin {
  margin: 0px auto;
}
</style>
<script>
let g_swapsBeforeAck = 15;
let g_canvas;
let g_gl;

function main()
{
  g_canvas = document.getElementById("c");
  g_gl = g_canvas.getContext("webgl", {desynchronized: true, preserveDrawingBuffer: true});
  requestAnimationFrame(draw);
}

function draw()
{
  g_gl.clearColor(1, 0, 0, 1);
  g_gl.clear(g_gl.COLOR_BUFFER_BIT);
  requestAnimationFrame(draw2);
}

function draw2()
{
  // the last frame is what should be visible when test ends
  g_gl.clearColor(0, 1, 0, 1);
  g_gl.clear(g_gl.COLOR_BUFFER_BIT);

  waitForFinish();
}

function waitForFinish()
{
  if (g_swapsBeforeAck == 0) {
    domAutomationController.send("SUCCESS");
  } else {
    g_swapsBeforeAck--;
    window.requestAnimationFrame(waitForFinish);
  }
}
</script>
</head>
<body onload="main()">
<div id="container" style="position:absolute; top:0px; left:0px">
<canvas id="c" width="100" height="100" class="nomargin" style="background-color:black"></canvas>
</div>
</body>
</html>
